> Binary compatibility is the reason. You can't break the memory model or the instruction set unless you actually have the ability to re-compile everything that

> Binary compatibility is the reason. You can't break the memory model or the instruction set unless you actually have the ability to re-compile everything that your users want to run. I fail to see how having shared speculation is incompatible with existing binaries. AMD processors for example check security before speculating, instead of just running things in parallel and hoping they don't need to reset registers later. Can you explain how speculative execution is systemic to x86? I can't see it to be honest.